Pay-per-call premium API access on Base via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com hosts a collection of pay-per-request API endpoints accessible via the x402 payment protocol on the Base network. The specific endpoint at `/api/v1/charges/289` is labeled "Premium API Access" and accepts POST requests. Payment is settled in USDC (contract 0x8335…2913 on Base) with a maximum charge of 20,000 base units, which equals $0.02 per request (USDC uses 6 decimals). No API keys, rate limits, or upfront commitments are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader lowpaymentfee.com platform advertises endpoints across four categories: Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, text summarization, classification, embeddings), Finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and Infrastructure utilities (geocoding, validation, conversion, generation). All listed endpoints share the same $0.02/request pricing.
Documentation is extremely sparse — the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI schema, no request/response examples, and no description of what the `/api/v1/charges/289` endpoint specifically returns. The endpoint is confirmed live (returns a proper 402 challenge), but the actual functionality behind this particular charge ID is unclear from available materials.
Capabilities
Use cases
- —Accessing premium API data without traditional API key registration
- —Making one-off paid API calls settled in USDC on Base
- —Agent-driven workflows that need keyless, per-request API access
Fit
Best for
- —Developers who want zero-signup, pay-as-you-go API access
- —AI agents with Base USDC wallets needing on-demand endpoints
- —Prototyping integrations without committing to subscription plans
Not for
- —Users who need detailed API documentation or guaranteed SLAs
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/289 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is confirmed live with a valid 402 challenge and clear pricing ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response examples, and no documentation beyond a wallet-connect prompt. The actual functionality of /api/v1/charges/289 is undescribed, making this effectively a stub listing.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README all show only 'Connect wallet'
- —No OpenAPI or schema describing request parameters or response format
- —The specific functionality of /api/v1/charges/289 ('Premium API Access') is not documented anywhere
- —Cannot verify what data or service is actually returned after payment
Citations
- —Endpoint returns 402 with x402 challenge accepting USDC on Base, maxAmountRequired 20000 base unitshttps://lowpaymentfee.com/api/v1/charges/289
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/charges/289
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Available API categories include Data & Analytics, AI & ML, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com